Arunachalam S

Breakage of buoyant drops using obstructions

Understanding passive breakage of drops in two phase systems is of crucial importance in industrial applications involving pulsed columns, agitated dispersions etc., Works in literature have majorly explored the impact of water drops in air on a variety of obstructions with a focus on the contact time but seldom mention anything about breaking drops in a two-phase system. We have conducted studies to probe into the outcomes of impingement of buoyant oil drops in water onto wedge shaped obstructions through high-speed imaging. A critical We is observed above which the impacting drops break. It is observed that a transition from center to off-center impingement can alter the outcome from breakage to no breakage. A surprising observation is that the variation of ratio of daughter drop volumes on breakage could not be explained by considering the slicing of the drops.
Further, It is found that changing the shape of the obstruction has an effect with the small-angled wedge breaking the drops easily compared to a wide angled wedge. Another interesting observation was the parent drop breaking and both the daughter droplets leaving on the same side of the obstruction.
To explain the above observations, a phenomenological model incorporating various forces in the system is being built up.